From: Leon Alrae <leon.alrae@imgtec.com>
To: Paolo Bonzini <pbonzini@redhat.com>, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PULL 08/21] rcu: run RCU callbacks under the BQL
Date: Wed, 25 Feb 2015 17:16:02 +0000 [thread overview]
Message-ID: <54EE0352.4020700@imgtec.com> (raw)
In-Reply-To: <1424110682-14334-9-git-send-email-pbonzini@redhat.com>
Hi,
On 16/02/2015 18:17, Paolo Bonzini wrote:
> This needs to go away sooner or later, but one complication is the
> complex VFIO data structures that are modified in instance_finalize.
> Take a shortcut for now.
It looks like this commit introduced a race condition. QEMU segfaults
very early in one of my tests where I boot Linux, and on one of my
machines it's easier to reproduce than on the others.
(gdb) bt
#0 0x00007ffff7b09fe3 in qemu_cpu_kick_thread (cpu=0x0) at
/slave/smoketest/src/cpus.c:1045
#1 0x00007ffff7b0a269 in qemu_mutex_lock_iothread () at
/slave/smoketest/src/cpus.c:1119
#2 0x00007ffff7ec5c39 in call_rcu_thread (opaque=0x0) at
/slave/smoketest/src/util/rcu.c:241
#3 0x00007ffff38489d1 in start_thread () from /lib64/libpthread.so.0
#4 0x00007ffff359586d in clone () from /lib64/libc.so.6
qemu_mutex_lock_iothread() passes first_cpu to qemu_cpu_kick_thread().
Sometimes this is happening before executing cpu_exec_init(), which I
believe is the reason why qemu_cpu_kick_thread() receives a null pointer.
Regards,
Leon
next prev parent reply other threads:[~2015-02-25 17:16 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-02-16 18:17 [Qemu-devel] [PULL 00/21] SCSI, RCU, KVM changes for 2015-02-16 Paolo Bonzini
2015-02-16 18:17 ` [Qemu-devel] [PULL 01/21] kvm_stat: Add kvm_exit reasons for aarch64 Paolo Bonzini
2015-02-16 18:17 ` [Qemu-devel] [PULL 02/21] qdev: support to get a device firmware path directly Paolo Bonzini
2015-02-16 18:17 ` [Qemu-devel] [PULL 03/21] vhost-scsi: add bootindex property Paolo Bonzini
2015-02-16 18:17 ` [Qemu-devel] [PULL 04/21] vhost-scsi: expose the TYPE_FW_PATH_PROVIDER interface Paolo Bonzini
2015-02-16 18:17 ` [Qemu-devel] [PULL 05/21] vhost-scsi: add a property for booting Paolo Bonzini
2015-02-16 18:17 ` [Qemu-devel] [PULL 06/21] vhost-scsi: set the bootable value of channel/target/lun Paolo Bonzini
2015-02-16 18:17 ` [Qemu-devel] [PULL 07/21] rcu: do not let RCU callbacks pile up indefinitely Paolo Bonzini
2015-02-16 18:17 ` [Qemu-devel] [PULL 08/21] rcu: run RCU callbacks under the BQL Paolo Bonzini
2015-02-25 17:16 ` Leon Alrae [this message]
2015-02-26 11:35 ` Paolo Bonzini
2015-02-26 13:40 ` Leon Alrae
2015-02-26 14:39 ` Paolo Bonzini
[not found] ` <54EF30AD.9040302@redhat.com>
[not found] ` <54EF425A.8010204@imgtec.com>
[not found] ` <1644893486.26759341.1424978182441.JavaMail.zimbra@zmail13.collab.prod.int.phx2.redhat.com>
[not found] ` <54F03A7D.90401@imgtec.com>
[not found] ` <54F06E59.2080609@redhat.com>
[not found] ` <54F07E28.6090004@imgtec.com>
2015-02-27 18:27 ` Paolo Bonzini
2015-02-16 18:17 ` [Qemu-devel] [PULL 09/21] memory: keep the owner of the AddressSpace alive until do_address_space_destroy Paolo Bonzini
2015-02-16 18:17 ` [Qemu-devel] [PULL 10/21] pcie: remove mmconfig memory leak and wrap mmconfig update with transaction Paolo Bonzini
2015-02-16 18:17 ` [Qemu-devel] [PULL 11/21] pci: split shpc_cleanup and shpc_free Paolo Bonzini
2015-02-16 18:17 ` [Qemu-devel] [PULL 12/21] docs: clarify memory region lifecycle Paolo Bonzini
2015-02-16 18:17 ` [Qemu-devel] [PULL 13/21] exec: introduce cpu_reload_memory_map Paolo Bonzini
2015-02-16 18:17 ` [Qemu-devel] [PULL 14/21] exec: make iotlb RCU-friendly Paolo Bonzini
2015-02-16 18:17 ` [Qemu-devel] [PULL 15/21] exec: RCUify AddressSpaceDispatch Paolo Bonzini
2015-02-16 18:17 ` [Qemu-devel] [PULL 16/21] rcu: introduce RCU-enabled QLIST Paolo Bonzini
2015-02-16 18:17 ` [Qemu-devel] [PULL 17/21] rcu: add g_free_rcu Paolo Bonzini
2015-02-16 18:17 ` [Qemu-devel] [PULL 18/21] exec: protect mru_block with RCU Paolo Bonzini
2015-02-16 18:18 ` [Qemu-devel] [PULL 19/21] cosmetic changes preparing for the following patches Paolo Bonzini
2015-02-16 18:18 ` [Qemu-devel] [PULL 20/21] exec: convert ram_list to QLIST Paolo Bonzini
2015-02-16 18:18 ` [Qemu-devel] [PULL 21/21] Convert ram_list to RCU Paolo Bonzini
2015-02-25 11:01 ` [Qemu-devel] [PULL 00/21] SCSI, RCU, KVM changes for 2015-02-16 Peter Maydell
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